The present invention relates to a system for the electrical transmission of an angular position, in particular from a measurement instrument to an indicating instrument, in which a transmitter and a receiver each have one rotor and one stator with multiple pairs of poles, and wherein alternating voltage is fed to a winding of the rotor of the transmitter, and voltages induced in the windings of the stator of the transmitter are transmitted to the windings of the stator of the receiver.
In particular, for the transmission of the angular position from a measurement instrument to an indicating instrument, systems are known in which the transmitter and the receiver (also called syncros) have the same mechanical construction, each having a rotor with a single pair of poles which is supplied with alternating voltage of, for instance, 400 Hz, and a stator with three pairs of poles. The stator of the transmitter produces by induction three alternating voltages the amplitudes of which change with the angular position of the rotor. The three alternating voltages produce in the similar coils of the receiver a magnetic field which is followed by the receiver rotor.
These known systems have proven themselves in particular due to their robust structure, but no torque is produced in the neutral position of the receiver rotor, so that as a result of friction a hysteresis is produced between the receiver rotor and the transmitter rotor.